Hay can some one help me I need the answers

For the equation below, x is the input and y is the output. y = -4x + 3 if the input is -8, then the output is

Matilda and kathryn went on different road trips over spring break.the equation below represents the number of miles matilda drove in x hours.y = 60xthe table below shows the number of miles kathryn drove in x hours.time(in hours)distance(in miles)114228342456who drove at a greater speed? a. matilda drove at a greater speed.b. matilda and kathryn drove at the same speed.c. kathryn drove at a greater speed.d.there is not enough information to determine their speeds

The rate of decay of a radioactive substance depends upon the amount present initially. the mass y (mg) of the radioactive substance cobalt-60 present in a sample at time t (years) is represented by the exponential equation y=50e −0.1315 t . answer the following questions in complete sentences. 1. how does the exponential equation above compare to the equation for simple interest that is compounded continuously? explain the similarities. 2. what is the initial amount of cobalt-60 in the sample? 2. how much cobalt-60 is left after 8.4 years? show your work. 3. what would be the y-intercept of the graph? what does it represent? 4. after how many years will the amount of cobalt-60 left be 6.25 mg? explain what happens to the cobalt-60 after 50 years? 5. discuss some “real-world” examples and uses of cobalt-60